1. Field of the Invention
The present invention refers to a new therapeutic application of acetyl-d,l-carnitine and other acyl derivatives of d,l-carnitine which are used as such or as pharmacologically acceptable salts in the therapy of myocardial anoxia, ischaemia, arrhythmic syndromes and heart failure, as well as in all those cases where the energy requirement of the heart increases due to fatigue. These acyl d,l-carnitine derivatives are also useful in protecting against adrenalin toxicity. They are remarkably superior to d,l-carnitine in respect to all these pharmacological actions.
2. Prior Art
The use of d,l-carnitine is well known especially in paediatrics for the treatment of lipid metabolism affections and in the dystrophic type muscular affections. Recently, d,l-carnitine has exhibited cardiotropic properties capable of resolving pathological situations characterized by cardiac rhythm disorders.
Moreover oxygen consumption in heart homogenates in the presence of acetyl-d,l-carnitine is markedly greater than oxygen consumption in the presence of d,l-carnitine and is independent from CoA additions (Table 1).
d,l-Carnitine and its use for treating heart failure have been described in U.S. Pat. Nos. 3,830,931 and 3,968,241. Esters of d,l-carnitine are also known to have physiological activity, and in particular have been found to excite contraction in the frog heart, as described in the German Pat. No. 719891. The pharmacological action of carnitine and its esters is known and described in the literature, e.g., Robert S. Harris et al, Vitamins and Hormones, Volume XV, Academic Press, Inc., 1957, pages 73-118. However, nothing in the literature has been found to disclose the remarkable increase in therapeutic properties of the particular esters of carnitine according to the present invention.